Device for stringing and tuning of strings in pianos, grand pianos, harpsichords, zithers and the like

ABSTRACT

The present invention relates to a device for stringing and tuning of strings in pianos, grand pianos, harpsichords, zithers and the like instruments. The device according to the present invention is mainly characterized in that the string is connected to one end of the rocker in such a way that at stringing the element will be clamped between the rocker and a bearing in the frame of the instrument, a special screw plate being arranged to hold the other end of the rocker clamped against the iron frame and to carry a fine tuning screw, by means of which fine tuning is accomplished in that way that the screw is acting on the arm of the rocker.

United States Patent 11 1 Sjiistrand et al.

[ June 24, 1975 DEVICE FOR STRINGING AND TUNING OF STRINGS IN PIANOS, GRAND PIANOS, HARPSICHORDS, ZITHERS AND THE LIKE [75] Inventors: Gunnar O. Sjiistrand, Atvidaberg;

St'affan G. Sjiistrand, Linkoping, both of Sweden [73] Assignee: Musikindustriell Forskning MIFO AB, Linkoping, Sweden 22 Filed: Apr. 5, 1974 21 App]. No: 458,403

Primary Examiner-Lawrence R. Franklin 5 7] ABSTRACT The present invention relates to a device for stringing and tuning of strings in pianos, grand pianos, harpsichords, zithers and the like instruments. The device according to the present invention is mainly characterized in that the string is connected to one end of the rocker in such a way that at stringing the element will be clamped between the rocker and abearing in the frame of the instrument, a special screw plate being arranged to hold the other end of the rocker clamped against the iron frame and to carry a fine tuning screw, by means of which fine tuning is accomplished in that way that the screw is acting on the arm of the rocker.

6 Claims, 5 Drawing Figures 3/1964 Costen 84/267 DEVICE FOR STRINGING AND TUNING OF STRINGS IN PIANOS, GRAND PIANOS,

HARPSICI-IORDS, ZITHERS AND THE LIKE The present invention relates to a device for stringing and tuning of strings in pianos, grand pianos, harpsichords, zithersandlike instruments. The devices of this kind, usedhitherto, generally comprise very primitive screw means where the string is wound around the screw. In this way the stringing will require quite a lot of time as will the tuning of the tone of the string, and it has shown that the tune often will be impermanent, partly by stretchingof the string and partly as the string will creep in its attachment. An accurate tuning will furthermore be obstructed-by the tendency :of the tuning screw to move by leapsat the stringing.

Already in the year. 1897 these problems had been observed, and the U.S.Pat. No..613,900 fromthis year discloses an improved device for stringing and tuning of pianos and the like, where for each string is provided a two-armed rocker, journalled in a steady iron frame and where one arm of the rocker is attached to the string and the other arm is influenced by a tuning screw or the like.

This device ought to have worked satisfactorily at the very tuning of the string, but the stringing, i.e. the fixing of the string at one arm of the rocker, was likely to be a rather time-consuming operation, which might explain why this device seemingly has not obtained any observable distribution on the market.

The present invention relates to a construction of the above-mentioned type but is characterized in that the stringing will be a fast and simple operation and that the fine tuning may be made to very great accuracy. It will also permit a rapid and easy changing of a broken string and is besides inexpensive to produce, which will permit the cost of this part of the manufacture of pianos and the like to be significantly reduced.

It will also afford a very good permanency according to tuning, as the attachment of the string is such that no creeping will occur. In order to make use of this stability properly it is suitable that also the other end of the string is fixed with a corresponding stability. Hitherto used loops, which have been spun in one end of the string, have shown a certain tendency to set after some time has passed, i.e. the tone has sunk.

The device according to the present invention is mainly characterized in that the string is connected to one end of the rocker in such a way that at stringing the string will either directly or influenced by an element connected with to the rocker, be clamped betwen the rocker and a bearing in the frame of the instrument, a special screw plate being arranged to hold the other end of the rocker clamped against the iron frame and to carry a fine tuning screw, by means of which fine tuning is accomplished in that way that the screw is acting on the arm of the rocker.

A number of different embodiments of the present invention are more closely illustrated on the attached drawings, on which FIG. 1 shows a rocker in stringing position.

FIG. 2 shows a lateral view of the same rocker in its final position after fine tuning.

FIGS. 3 and 4, respectively, and 5 and 6, respectively, show the same views of two other embodiments of the rocker.

FIG. 7 shows a detail of the string attachment at the embodiment shown in FIGS. 5 and 6.

In the figures'the string is denoted by l and the rocker by 2. A hole 3 in the rocker makes'a guidance for the string 1 at installation, and 4 denotes a guidance of the rocker for the string, suitably designed as a groove. Y

The carrying frame of the instrument is denoted by 5, having a journalling beam 6 for all rockers.

The frame 5 is by strong bolts 12 joined to an iron plate 9 having in it arranged holes 10 for screwbricks 8, and these are carrying tuning screws which cooperate with one of the arms of the rocker.

The rockers are besides provided with a groove (key grip) for cooope ration with a suitable tuning key 14,which can be designed as a chisel or the like. The

attachment of the stationary end of the string is hinted These features are common for the illustrated three various embodiments and assembling and fine tuning is performed in the following way:

The rocker 2 is placed on the journalling 6 of the instrument on the frame 5, whereafter the string 1, which is fastened at its other end (at 13) is threaded through the hole 3 in the rocker, whereafter the string is bent and sheared. The rocker 2 then should be approximately in that position which is obvious from FIGS. 1, 3 and 5. Thereafter the rockers (or rocker) are tuned to horizontal position, which suitably is performed by means of the tuning key 14, mentioned above, in cooperation with the groove 15.

At the same time as th rocker 2 (rockers) is kept in this position the screw plate 8 is inserted into the groove 10 in the plate 9, joined to the frame 5, and the screw plate now will keep the rocker (rockers) when the tuning key is removed.

Then the tuning screws 11 are applied by means of which fine tuning is accomplished.

At that embodiment which is shown in FIGS. 1 and 2, the hole 3 for the string 1 in the rocker 2 is bored in such a way that the string will lie freely for a section of the bottom side of the recess for the journalling 6 in the rocker. Accordingly, the string will, when it is stretched, be clamped between the rocker and the journalling 6, and will be attached against sliding if the bent part of the string should show tendency to float. This embodiment has shown completely satisfactory for coarse strings but not quite safe as to slender strings. This might be due to the fact that the friction coefficient between piano wire and cast iron is rather low and those embodiments which are illustrated in FIGS. 3-7 are characterized in that the rocker 2 is provided with a resilient tongue 16, the lower side of which bears on the journalling 6 and the upper side of which forms the underside of a groove in which the string 1 is extending and the upper side of which is formed by the underside of the rocker 2.

At assembling the string 1 will be clamped between the resilient tongue 16 and the rocker itself. As the rocker is made of a relatively soft material the friction on the upper and lower side of the string will be considerably greater, and a completely satisfactory clamping also of more slender threads is achieved. In the above specification has been mentioned the iron frame etc. It should be appreciated that for different types of instruments other material can come to use, for instance, aluminum or laminated wood. It should also be appreciated'that the clamping of the strings on the rocker will be more effective, if a moderately soft material, for instance-aluminum will be utilized.

From manufacturing point of view it may be suitable to make each rocker from three punched plates pieces which then are spot welded together. Thus by giving the central plate a suitable form, the desired groove shaped guidings for the string are. easily achieved.

We claim:

1. In a device for stringing and tuning of the strings in pianos and like stringed instruments, wherein an elongated rocker is journalled on a fixed arcuate abutment to be swung about an axis transverse to the direction of the string, the string being suspended from the rocker at a point spaced from one side of the axis of said abutment. the rocker being in engagement with adjustable tuning means at a location spaced from the other side of said axis, the improvement which comprises a movable clamping element connected with said rocker, the lower surface of said clamping element being in sliding contact with said abutment, the upper surface of said clamping element being disposed below the lower surface of said rocker for resiliently clamping the string between said element and rocker.

2. The invention defined in claim 1, wherein said clamping element comprises a tongue formed integrally with the rocker.

3. The invention defined in claim 1, wherein the lower side of the rocker is provided with an upwardly directed recess spaced from one end of the rocker, said clamping element being disposed in said recess, and a longitudinal bore is provided in the rocker at said one end to admit the string to the upper part of said recess.

4. The invention defined in claim 1, wherein said rocker comprises a material having a coefficient of friction with respect to piano wire which is greater than that of cast iron.

5. The invention defined in claim 4, wherein said rocker comprises aluminum. t

6. The invention defined in claim 1, wherein said rocker is provided with a passage for conducting said string from said clamping element to the exterior of the rocker. 

1. In a device for stringing and tuning of the strings in pianos and like stringed instruments, wherein an elongated rocker is journalled on a fixed arcuate abutment to be swung about an axis transverse to the direction of the string, thhe string being suspended from the rocker at a point spaced from one side of the axis of said abutment, the rocker being in engagement with adjustable tuning means at a location spaced from the other side of said axis, the improvement which comprises a movable clamping element connected with said rocker, the lower surface of said clamping element being in sliding contact with said abutment, the upper surface of said clamping element being disposed below the lower surface of said rocker for resiliently clamping the string between said element and rocker.
 2. The invention defined in claim 1, wherein said clamping element comprises a tongue formed integrally with the rocker.
 3. The invention defined in claim 1, wherein the lower side of the rocker is provided with an upwardly directed recess spaced from one end of the rocker, said clamping element being disposed in said recess, and a longitudinal bore is provided in the rocker at said one end to admit the string to the upper part of said recess.
 4. The invention defined in claim 1, wherein said rocker comprises a material having a coefficient of friction with respect to piano wire which is greater than that of cast iron.
 5. The invention defined in claim 4, wherein said rocker comprises aluminum.
 6. The invention defined in claim 1, wherein said rocker is provided with a passage for conducting said string from said clamping element to the exterior of the rocker. 